Particle removal from electrochromic films using non-aqueous fluids

ABSTRACT

Several of the films that comprise various energy producing or control devices, for example, electrochromic devices, lithium batteries, and photovoltaic cells, are sensitive to moisture in some way. They may be especially vulnerable to moisture at particular stages during their fabrication. It may also be highly desirable during fabrication to be able to wash particulates from the surface. The particulates may be generated some aspect of the fabrication process, or they may arise from the environment in which the fabrication takes place. This invention shows ways to remove said particles from the surface without incurring the damage associated with typical washing processes, resulting in higher manufacturing yields and better device performance.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of and claims priority under 35 U.S.C.§ 120 to U.S. patent application Ser. No. 14/198,824, entitled “PARTICLEREMOVAL FROM ELECTROCHROMIC FILMS USING NON-AQUEOUS FLUIDS,” by HarveyKALWEIT et al., filed Mar. 6, 2014, which is assigned to the currentassignee hereof and is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Large area electronic energy control, display or lighting products thatare permanently mounted in structures, such as buildings, ships,aircraft, trains, buses, or cars, may include electronic orelectro-optical devices (collectively “electronic energy controldevices”), such as electrochromic, OLED, electroluminescent,electro-reflective, LCD, and other monolithic display or lightingdevices, in which an electronically and optically active media iscontained between closely spaced electrodes. The appearance of thelighting or a display created by such electronic energy control devicesmay be adversely affected by the presence of defects in the active orinactive media that locally modify the potential between the electrodes.

Electronic energy control devices by also be used to modify lighttransmission over small areas, for example, displays, illuminators,vision systems, sensors, and similar devices. The undesirable effect ofa defect is even greater when the size of the device becomes similar to,or even smaller, that the area affected by the defect.

For example, electrochromic devices include electrochromic materialsthat are known to change their optical properties, in response toapplication of an electrical potential, so as to make the device, forexample, more or less transparent or reflective, or have a desiredcoloration.

The manufacture of an electrochromic device typically includes formingan electrochromic (EC) film stack including a plurality of layers ofconductive and electrochromic material on a substrate, such as glass.See, for example, U.S. Pat. Nos. 5,321,544, 6,856,444, 7,372,610 and7,593,154, incorporated by reference herein. During the manufacturingprocess, defects sometimes may be formed in one or more of the layers ofthe EC film that can cause the electrochromic device to have a differentoptical behavior than desired, or lack a desired optical behavior, at ornear the location of the defect when the device is operated by applyingan electrical potential thereto. The defect may be a short betweenconductive layers of the EC film stack caused, for example, by foreigncontaminants, or a material non-uniformity or scratch in one or more oflayers of the EC film stack, that causes the EC device, when operated,to have at the location of the defect optical properties different thanthose desired and present at locations adjacent to the defect. Thedefect, hence, may cause the EC device to have an undesirable aestheticappearance when operated.

Although various techniques are known and may be performed to repair adefect in an electronic energy control device, such as an electrochromicdevice, during manufacture, some defects still may remain in a final,manufactured electronic energy control device product. For example, anelectrochromic device included in a final, manufactured electrochromicdevice product, such as an insulated glass unit (IGU), may includedefects visible only when the electrochromic device transitions betweenan energized and non-energized state, and defects not visible in visibleor near infrared light. Oftentimes, such defects are noticed or appearonly after installation of the electrochromic device product, forexample, as an exterior window in a high rise building. It is alwaysmore desirable to eliminate the cause of a defect than to try to repaira defect after it has occurred.

It is desirable to reduce the total number of defects or, if possible,completely eliminate all visual or non-visual defects. During themanufacturing of an EC device, or related devices, particulate materialor other contaminants may be introduced. For example, the vacuum processfor the deposition of the film stack in electrochromic devices may beinterrupted at some point in between the deposition of the upper andlower electrical conductors for the purpose of patterning the lowerconductor into the proper electrical circuit. After patterning the lowerconductor (so that the appropriate electrical connections can be madeand voltage applied), EC device processing continues by deposition ofthe remainder of the film stack. Particles may be generated by theremoval, patterning, and other steps between the two deposition stepscan have visible defects in the completed EC device, including, as notedabove, those defects which may become visible to the operator.

Conventional application of water to remove particulate contaminantsmay, in some instances, leave water spots, stains, or water flowpatterns. Depending on the nature of the substrate or surface beingexposed to the water treatment or cleaning, the substrate may bleach,discolor, or become less electrically efficient. In a worst casescenario, water could lead to uniformity differences in coloration of ECdevices. Such water-induced defects may only appear during dynamicswitching of an electrochromic device, making them difficult to detect,yet sill unappealing to users of the device. There remains the need toremove particulate material or other contaminants generated during themanufacturing process without degrading any of the material surfaces orfilm stacks present in an EC device or other like device (EC device,photochromic device, thermochromic device, liquid crystal display,organic light emitting diode, batteries, or individual thin filmmaterials in other discrete or stand-alone applications).

BRIEF SUMMARY OF THE INVENTION

In one aspect of the present invention is a method of preparing asubstrate for the receipt of a film or coating material to be depositedin communication with the substrate.

In another aspect of the present invention is a method of preparing asubstrate for the receipt of a film or coating material to be depositedin communication with the substrate, where the substrate is at leastpartially contaminated with particulate matter.

In another aspect of the present invention is a method of preparing asurface of a substrate comprising either directing a stream ofnon-aqueous liquid or otherwise exposing the substrate to a non-aqueousliquid, the surface comprising particulate material, and removing atleast a portion of the non-aqueous liquid and at least about 80% of theparticulate material from the surface. In some embodiments, at leastabout 90% of the particulate material is removed from the surface.

In another aspect of the present invention is a method of preparing anelectrochromic device, comprising: (a) depositing a first conductivelayer on a substrate; (b) pattering the first conductive layer; (c)removing particulate material ejected from the pattering from a surfaceof the first conductive layer, the material removed by directing astream of non-aqueous fluid towards the surface; (d) depositing one ofan electrochromic layer or a counter electrode layer on the firstconductive layer, thereby providing a first deposited electrode, (e)depositing an ion-conductor layer on the first deposited electrode, (f)depositing the other of the electrochromic layer or the counterelectrode layer on the ion-conductor layer, thereby providing a seconddeposited electrode, and (g) depositing a second conductive layer on thesecond deposited electrode.

In some embodiments, the non-aqueous liquid comprises about 10% water.In other embodiments, the non-aqueous liquid comprises about 5% water.In other embodiments, the non-aqueous liquid comprises about 1% water.In other embodiments, the non-aqueous liquid comprises about 0.1% water.In other embodiments, the non-aqueous liquid comprises less than about0.01% water.

In some embodiments, the non-aqueous liquid is non-polar. In someembodiments, the non-aqueous liquid is polar. In some embodiments, thenon-aqueous liquid is characterized by a specified range of values ofpolar moment. For example, polar solvents may be classified as thosehaving a molecular dipole moment of about 1.4 Debeye to about 5.0Debeye, with water being about 1.85 Debeye. Non-polar solvents may beclassified as having molecular dipole moments from about 0.0 Debeye toabout 1.1 Debeye. Very strongly non-polar solvents, such as pentane andhexane, have moments very close to 0.0 Debeye. Semi-polar solvents arefound at all values of dipole strength in between these extremes, andspecific values may be desirable in certain instances. All liquids willfit somewhere on this gradient. In some embodiments, the non-aqueousliquid comprises a fluorocarbon, hydrofluorocarbon, or surfactant. Insome embodiments, the particulate material has a size ranging frombetween about 1 μm to about 1 mm. In other embodiments, the particulatematerial has a size ranging from between about 1 μm to about 500 μm. Inother embodiments, the particulate material has a size ranging frombetween about 1 μm to about 250 μm.

In some embodiments, an energy is applied to the non-aqueous liquid toassist in removing the particulate material.

In some embodiments, the electrochromic device has less than about 1defect per 1 square meter. In some embodiments, the substrate is alaminate. In some embodiments, the electrochromic device is part of aninsulated glass unit. In some embodiments, the insulated glass unitfurther comprises a photovoltaic device. In some embodiments, theelectrochromic device is heat treated. In some embodiments, lithium isinserted into at least one of the first or second electrodes or the ionconductor layer.

In another aspect of the present invention is a method of preparing asurface of a substrate comprising directing a stream of non-aqueousliquid or exposing the surface being prepared to a non-aqueous liquid,the surface comprising particulate material having a size between about1 μm and about 1 mm, and removing at least about 98% of the non-aqueousliquid and at least about 90% of the particular material from thesurface.

In some embodiments, the surface is comprised of a silicate glass, anon-silicate glass, a crystal, such as silicon, germanium, sapphire,lithium niobate, alkali earth titanates, a polymer, a copolymer, aliquid crystal polymer, a film of inorganic material, a film of organicmaterial, or a composite of organic material and inorganic material. Insome embodiments, the surface is a conductive layer of an electrochromicdevice, a battery, a photovoltaic device, a thermochromic device, aliquid-crystal display device, an organic light emitting diode device,or a zenithal bistable device. Conductive layers could comprise metals,for example, gold, silver, copper, nickel, or aluminum, transparentconducting oxides, for example, indium tin oxide, aluminum zinc oxide,fluorinated tin oxide, and carbon based materials such as graphemesheets, fullerene and graphite nanotube coatings. In some embodiments,the surface is a non-conductive layer of an electrochromic device, abattery, a photovoltaic device, a thermochromic device, a liquid crystaldisplay device, an organic light emitting diode device, zenithalbistable device. In some embodiments, the surface is a conductive layerof an electrochromic device. In some embodiments the surface is part ofthe substrate that also supports the electrochromic or other energydevice.

In some embodiments, the conductive surface consists of a metal, forexample, gold, silver, copper, aluminum, nickel, titanium, niobium, tin,indium, or a metal alloy, for example brass or stainless steel.

In other embodiments, the conductive surface consists of a non-metallicconductor, for example indium tin oxide, aluminum zinc oxide,fluorine-doped tin oxide, and similar materials.

In yet other embodiments, the conductive surface consists of a form ofgraphite, such as graphene sheets, nanotubes, fullerene spheres, coatedor bonded to a substrate, or forming the substrate itself.

In some embodiments, the non-aqueous liquid comprises less than about10%. In other embodiments, the non-aqueous liquid comprises about 5%water. In other embodiments, the non-aqueous liquid comprises about 1%water. In other embodiments, the non-aqueous liquid comprises about 0.1%water. In other embodiments, the non-aqueous liquid comprises less thanabout 0.01% water.

In some embodiments, the non-aqueous liquid is non-polar. In someembodiments, the non-aqueous liquid is polar. In some embodiments, thenon-aqueous liquid is characterized by a specified range of values ofpolar moment. A liquid with a molecular dipole moment greater than about1.4 Debeye is considered polar, while one with a molecular dipole momentfor less than about 1.1 Debeye is considered non-polar. Semi-polarliquids exist with molecular dipole moments between these values. Insome embodiments, the non-aqueous liquid comprises a fluorocarbon,hydrofluorocarbon, or a surfactant. In some embodiments, the particulatematerial has a size ranging from between about 1 μm to about 1 mm. Insome embodiments, the energy is applied to the non-aqueous liquid toassist in removing the particulate material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a particular washer concept.

FIG. 2 provides for a process flow chart.

DETAILED DESCRIPTION

In one embodiment is method of preparing a substrate or the surface of asubstrate for the receipt of a film or coating material to be depositedin communication with the substrate. In another embodiment is a methodof preparing a substrate for the receipt of a film or coating materialto be deposited in communication with the substrate, where the substrateis at least partially contaminated with particulate matter. In someembodiments, the particulate material comprises material removed fromthe surface of the substrate in a prior process step (e.g. particulatedefects). In some embodiments, at least about 90% of a particulatematerial having a size greater than 2 μm is removed from the surface ofthe substrate.

In another embodiment is a method of removing particles from a substratesurface, or a surface of a film stack deposited therein, withoutaffecting the appearance of a device comprising the substrate or filmstack. In some embodiments, the device is an electrochromic device, anLCD panel, a photovoltaic device, a thermochromic device, a battery, orany other equivalent device that employs at least one thin film in itsoperation. In some embodiments the method employs removing particulatedefects with a non-aqueous solution, provided that the non-aqueoussolution used does not substantially interact with the substrate or thefilms deposited on the substrate.

In general, the method employs exposing the surface to be cleaned to anon-aqueous fluid, particularly with the addition of some source ofenergy to enable this fluid to dislodge particles from the surface. Thesurface may include any substrate, including those comprised of glass,polymers, organic or inorganic thin films (including those films thatmake up the various layers of electrochromic devices, photovoltaicdevices, thermochromic devices, LCDs, etc.). A stream of non-aqueousfluid may be directed at a specific angle incident to the surface of thesubstrate and provided at a specific pressure, force, or energy to besteffect removal of particular matter. Any stream angle or pressure,force, or energy may be employed provided it does not cause damage tothe surface of the substrate or any underlying layers that are present.Other forms of energy may be introduced into the liquid to dislodgeparticulates, for example ultrasonic vibration, bubble jet impact,laser-induced thermal shock, vapor condensation, and motion of brushes.

In some embodiments the particular matter is made of a material that isthe same as a material of the underlying substrate. Without wishing tobe bound by any particular theory, it is believed that any particulatematter left behind could create visible defects in any completed device(e.g. electrochromic device) or could create short circuits in a device(e.g. a battery or smart window).

In some embodiments, the particles to be removed have a size rangingfrom between about 1 μm to about 1 mm. In other embodiments, theparticulate material has a size ranging from between about 1 μm to about500 μm. In other embodiments, the particulate material has a sizeranging from between about 1 μm to about 250 μm. In yet otherembodiments, the particles to be removed have a size ranging frombetween about 2 μm to about 200 μm. In some embodiments, between about70% and about 95% of particles having a size between about 2 μm andabout 200 μm are removed.

By way of example, in some embodiments a conductive layer is depositedon a glass substrate, and material is removed from the conductive layerin a process to pattern a shape into the conductive layer. The materialejected from by patterning process (which is of itself comprised largelyof the material constituting the conductive oxide layer itself) could beleft behind on the surface of the conductive layer and is desirable tobe removed.

In some embodiments, the non-aqueous fluid stream is directed toward thesurface to be prepared through a bubble jet. A bubble jet employs a highenergy jet of liquid from a special nozzle to force particles away fromthe surface in such a manner that the particles may be flushed away andremoved or collected. The bubble jet does this in a manner that does notdamage the surface being prepared or any of the underlying layers orfilm sticks beneath the surface being prepared.

In other embodiments, the non-aqueous fluid is applied to a surface andthen brushes or air streams are used to flush and remove or loosenparticulate matter. The non-aqueous fluid may also be applied and energysupplied from ultrasonic transducers to affect mechanical energytransfer to the particulate matter and ultimately flushing or looseningof the material from the substrate or surface to be prepared.

The person of ordinary skill in the art would be able to envision othermeans through which mechanical energy may be applied, in conjunctionwith the non-aqueous fluid, to affect a flushing or loosening ofparticulate matter from the substrate or surface to be prepared bytransferring the applied mechanical or kinetic energy to the particulatematter.

Fluids having low surface energies, for example, 3M Novec 7300, are usedto advantage because this property assists in keeping particles removedfrom a surface in suspension. Proper surfactants added to a highersurface energy non-interacting non-aqueous fluid may be used toadvantage for the same purpose.

The non-aqueous fluid may be any fluid that does not interact with thesubstrate or surface being prepared or any layer in communication withthe surface being prepared. In some embodiments, the non-aqueous liquidis a non-polar organic liquid. In other embodiments, the non-aqueousliquid is a polar organic liquid. In other embodiments, the non-aqueousliquid is an organic liquid having a polar moment with a specifiedrange. In other embodiments, the non-aqueous liquid is a polar proticsolvent. In yet other embodiments, non-aqueous liquid is a polar aproticsolvent.

In some embodiments, the non-aqueous fluid contains a certain percentageof water. For example, the non-aqueous solution may be a mixture of anon-aqueous organic liquid and water, where the solution may contain upto 0.01% water, provide that the non-aqueous organic liquid and waterare miscible. If the non-aqueous liquid contains water, the water ispreferred to be deionized water or distilled water.

In some embodiments, the non-aqueous liquid is selected from one that isnon-flammable. In some embodiments, the non-aqueous liquid is selectedfrom one that is relatively non-toxic. In some embodiments, thenon-aqueous liquid is selected from one that is recyclable (e.g. wherethe particulate matter could be removed from the liquid, and the liquidreused in subsequent processing). In yet other embodiments, thenon-aqueous liquid is an oil with a high flash point, such as thosecommonly used to store lithium.

In some embodiments, the non-aqueous liquid is pentane, hexane,cyclohexane, benzene, toluene, chloroform or diethyl ether, or mixturesthereof. In other embodiments, the non-aqueous liquid is dichlormethane,tetrahydrofuran, or ethyl acetate or mixtures thereof. In yet otherembodiments, the non-aqueous liquid is t-butanol, n-propanol, ethanol,methanol, terpineol, acetic acid, or mixtures thereof, with or withoutthe addition of water.

In some embodiments, the non-aqueous liquid is selected based on thematerial comprising the particulate defect, such that chemical orphysical interactions may exist between the particulate matter and theliquid to assist in the removal of the particulate matter from thesurface being prepared. For example, van der Waals forces or hydrogenbonds may temporarily exist between the liquid and the particulatematter aiding in the flushing or loosening of the matter from thesurface being prepared (and, in some examples, this would allow loweringof the mechanical energy supplied to the surface or liquid stream). Oneskilled in the art will be able to select an appropriate liquid andmechanical energy supplied to best flush or loosen materials off thesubstrate or surface and to prevent damage to the surface or layers incommunication with the surface.

In some embodiments, the non-aqueous liquid is a halogenated liquid. Insome embodiments, the halogen is fluorine. In some embodiments, thenon-aqueous liquid is a hydrofluorocarbon liquid. In other embodiments,the non-aqueous liquid comprises a fluorocarbon. In yet otherembodiments, the non-aqueous liquid is a polymeric fluorinated solvent.In yet further embodiments, the non-aqueous liquid comprises asurfactant. In yet further embodiments, the non-aqueous liquid iscomposed of a non-interacting fluid with the addition of a differentsurfactant.

Preferred non-aqueous liquids will have at least one of the followingproperties: (1) only minimally interacts with the surface beingprepared; (2) leaves minimal stains or deposits; (3) is readilyremovable; (4) is relatively non-toxic or non-carcinogenic; (5) lowinteraction with the environments (e.g. ozone depletion; greenhouseeffect); (6) non-flammable or of low flammability; (7) relativelynon-corrosive; (8) cost effective; and (9) provides little interactionwith upstream or downstream processes (e.g. common washer constructionmaterials).

One example of a family of hydrofluorocarbon liquids is available from3M under the trade name Novec™. Four examples of 3M Novec™ liquidsinclude 7300, 7200, 7100, and 71IPA. Applicants have found that 71IPAwas found to increase film marks similar to those marks left behind fromwater. However, Applicants have observed that no marks were left fromthe other liquids in this group. In addition, Applicants have foundthese liquids to have a suitable low toxicity and are non-flammable, orweakly flammable, making integration into the industrial environmentsafer than many hydrocarbon based liquids. Moreover, Applicants havefound that the fluorocarbon based liquids mark less, cause lessbleaching to the surface material to which it is applied, or alter thecolor or optical density of the surface or dynamic switching rate of anyfilm layers in communication thereof.

In other embodiments, the non-aqueous liquid comprises 3M Novec™ 4200,3M FC-4434, 3M Novec™ 4300, 3M FC-4432, 3M Novec™ fluid HFE-7000, 3MNovec™ fluid HFE-7100, 3M Novec™ fluid HFE-7200, 3M Novec™ fluidHFE-7500, 3M Novec™ fluid HFE-71IPA, 3M Fluorinert™ FC-72, 3MFluorinert™ FC-84, 3M Fluorinert™ FC-77, 3M Fluorinert™ FC-3255, 3MFluorinert™ FC-3283, 3M Fluorinert™ FC-40, 3M Fluorinert™ FC-43, 3MFluorinert™ FC-70, and/or 3M FC-4430. In an exemplary embodiment, thenon-aqueous liquid comprises 3M Novec™ 4200, 3M FC-4434, 3M Novec™ 4300,3M FC-4432, 3M Novec™ fluid HFE-7000, 3M Novec™ fluid HFE-7100, 3MNovec™ fluid HFE-7200, 3M Novec™ fluid HFE-7500, 3M Fluorinert™ FC-72,3M Fluorinert™ FC-84, 3M Fluorinert™ FC-77, 3M Fluorinert™ FC-3255, 3MFluorinert™ FC-3283, 3M Fluorinert™ FC-40, 3M Fluorinert™ FC-43, 3MFluorinert™ FC-70, and/or 3M FC-4430. In some embodiments, the liquidhas a fluoride concentration, by weight, based on active content,ranging between about 1 ppm and about 50,000 ppm. For example, suchfluoride concentration may range between about 100 ppm and about 5000ppm. has a fluoride concentration, by weight, based on active content,ranging between about 1 ppm and about 50,000 ppm. For example, suchfluoride concentration may range between about 100 ppm and about 5000ppm.

Other non-aqueous liquids include a fluoride surfactant that may be orcontain a composition according to the formula: Rf-SO₃ ⁻M⁺, where the Rfis a C1 to C12 perfluoroalkyl group, and M⁺ is a cation, a H⁺ atom or anammonia group. In some embodiments, the fluoride surfactant may be orcontain a composition according to the formula: Rf—SO₂N⁻—R¹M⁺, where theRf is a C1 to C12 perfluoroalkyl group; R¹ is H, an alkyl group, ahydroxyalkyl group, an alkylamine oxide group, an alkylcarboxylate groupor aminoalkyl group; and M⁺ is a cation, a H⁺ atom or an ammonia group.The alkyl, hydroxylalkyl, alkylamine oxide, alkylcarboxylate oraminoalkyl groups of R¹ groups may have from 1 to 6 carbon atoms. Thehydroxylalkyl group may have the formula —(CH₂)x-OH, where x is aninteger from 1 to 6.

Other noon-aqueous liquids include a fluoride surfactant may be orcontain a composition according to the formula: Rf-Q-R¹SO₃M⁺, where theRf is a C1 to C12 perfluoroalkyl group; R¹ is alkylene of the formula—CnH2n(CHOH)oCmH2m-, the n and m are independently 1 to 6 and o is 0 to1, and is optionally substituted by a catenary oxygen or nitrogen group;M⁺ is a cation; Q is —O— or —SO₂NR²—; and the R²— is an H—, alkyl, aryl,hydroxyalkyl, aminoalkyl, or sulfonatoalkyl group, optionally containingone or more catenary oxygen or nitrogen heteroatoms. The alkyl, aryl,hydroxyalkyl, aminoalkyl, or sulfonatoalkyl group may have from 1 to 6carbon atoms. The hydroxyalkyl group may be of the formula—C_(p)H_(2p)—OH, where the p is an integer from 1 to 6. The aminoalkylgroup may be of the formula —C_(p)H_(2p)—NR³R⁴, where the p is aninteger of 1 to 6 and R³ and R⁴ are independently H or alkyl groups of 1to 6 carbon atoms. The R¹ group is —CnH2nCH(OH)CmH2m-, and the n and mare independently 1 to 6.

In some embodiments, the non-aqueous liquid is recovered or recycled.For example, the solvent may be filtered to remove particles above acertain size by methods such as vacuum or atmospheric distillation,sub-micro filtration, or sorption filtration.

In one test of non-aqueous liquid exposure, a device substrate waspaused on a horizontal conveyor after an electrochromic (EC) layer hadbeen deposited. Several non-aqueous liquids were applied to the surfaceof the EC film, in quantities of approximately 1 cm³, and allowed topool on the surface for about 10 seconds. These liquids were applied inlocations that were carefully measured and recorded, to allow subsequentobservation of the exact locations treated. After about 10 seconds ofelapsed time, an air jet was used to blow the pool of liquid across thedevice. At this point, no marks associated with the liquids were visibleon the surface. This substrate was then further processed. Afterprocessing, this device (an electrochromic device) was colored andbleached according to standard test protocols, and the measuredlocations at which the test liquids had been applied were carefullymonitored.

Five liquids were used in this experiment: deionized water (control); 3MNovec 7300; 3M Novec 7200; 3M Novec 7100; and 3M Novec 71IPA. Thepresence of water in the test as a control insured that this particularfilm stack did in fact exhibit its characteristic sensitivity to water,and so assured us that were dealing with a film stack that behaved inthe expected manner. The results are shown in the following Table A:

Liquid: Test 1 Test 2 DI water very strongly not used marked Novecstrongly marked strongly 71IPA marked Novec no visible marks no visible7100 marks Novec no visible marks no visible 7200 marks Novec no visiblemarks no visible 7300 marks

Test 2: Test 2 was a repeat of Test 1, except that water was not used asthe control. The marking of the electrochromic device produced by 3MNovec 71IPA was so similar to that of water that the water was omittedto allow a larger area of the device to be exposed to each of the four3M Novec non-aqueous solvents. In each case, the non-polar, highlyinert, pure Novec fluorinated solvents, left no marks at all visible inthe electrochromic device during coloring or bleaching. The water leftmottled light areas with dark edges around the original pool location,and dark-edged light streaks in areas over which the liquid had beenblown by the applied air jets. These defects showed up at various pointsin the coloring and bleaching cycles, as well as in the final fullycolored state, and were characterized by differences in switching rate,as well as ultimate optical density. Novec 71IPA, which is a combinationof Novec 7100 and isopropanol (IPA), showed behavior very similar tothat of water, but a little less strongly marked. Novec 7100, along withNovec 7200 and Novec 7300, showed no marking of the electrochromicdevices at all, while bleaching, coloring, or in transition. The lack oftransitional defects is a critical point, since lowered switching speedis the first indication of an interaction between the cleaning fluid andthe electrochromic device.

A flat glass washer using bubble jet energy and 3M Novec 7300 has beendesigned and constructed to demonstrate the effectiveness of this methodof particle removal, without damage the electrochromic films. A drawingof this system is found in FIG. 1.

Process flow diagram showing alternate locations for patterning andnon-aqueous cleaning of particulate debris. The cleaning step can beinserted wherever particulate removal helps yield and quality. Theprocess flow using patterning/cleaning step B only is preferred.

1. An electrochromic device prepared by a process comprising the stepsof: depositing a first conductive layer over a substrate; depositing afirst electrode layer over the first conductive layer, wherein the firstelectrode layer is one of an electrochromic layer or a counter electrodelayer; depositing an ion conductor layer over the first electrode layer,wherein a film stack includes the first conductive layer, the firstelectrode layer, and the ion conductor layer; exposing the ion conductorlayer to a non-aqueous liquid to remove particulate material having asize between about 0.1 μm and about 1000 μm, wherein the non-aqueousliquid is selected from the group consisting of a hydrofluorocarbon, afluorocarbon, a polymeric fluorinated solvent, and a fluoridesurfactant; depositing a second electrode layer over the film stackafter exposing the ion conductor layer to the non-aqueous liquid,wherein the second electrode layer is the other of the electrochromiclayer or the counter electrode layer; and depositing a second conductivelayer on the second electrode layer, wherein the electrochromic devicehas a defect density of less than 1 defect/m².
 2. The electrochromicdevice of claim 1, wherein the electrochromic device is configured foruse in a window.
 3. The electrochromic device of claim 1, wherein thenon-aqueous liquid is delivered to a surface of the substrate in theform of a stream or jet of sufficient velocity to dislodge at least someof the particulate material from the surface on which it impinges. 4.The electrochromic device of claim 1, wherein the temperature of thenon-aqueous liquid and of a surface of the substrate are independentlycontrolled.
 5. The electrochromic device of claim 1, wherein thenon-aqueous liquid comprises less than about 0.1% of water.
 6. Theelectrochromic device of claim 1, wherein the first electrode layer isthe electrochromic layer, and the second electrode layer is the counterelectrode layer.
 7. The electrochromic device of claim 1, wherein thenon-aqueous liquid is non-polar.
 8. The electrochromic device of claim1, wherein the non-aqueous liquid is polar.
 9. The electrochromic deviceof claim 1, wherein the non-aqueous liquid comprises a fluorocarbon,hydrofluorocarbon, or a polymeric fluorinated solvent.
 10. Theelectrochromic device of claim 1, wherein an energy is applied, theenergy selected from the group consisting of ultrasonic agitation of theliquid, bubble jet agitation, and thermal heating of the liquid.
 11. Theelectrochromic device of claim 1, further comprising lithiating theelectrochromic layer, the ion conductor layer, or the counter electrodelayer.
 12. The electrochromic device of claim 1, further comprisingpatterning the film stack before exposing the film stack to thenon-aqueous liquid.
 13. The electrochromic device of claim 1, whereinthe defect density is less than 1 short circuit/m².
 14. Theelectrochromic device of claim 1, wherein the defect density is lessthan 1 visible defect/m².
 15. The electrochromic device of claim 1,wherein the non-aqueous liquid has a fluoride concentration, by weight,based on active content, ranging between about 1 ppm and about 50,000ppm.
 16. The electrochromic device of claim 1, wherein the fluoridesurfactant includes: Rf—SO₃ ⁻M⁺, where the Rf is a C1 to C12perfluoroalkyl group, and M⁺ is a cation, a H⁺ atom or an ammonia group;or Rf—SO₂N⁻—R¹M⁺, where the Rf is a C1 to C12 perfluoroalkyl group; R¹is H, an alkyl group, a hydroxyalkyl group, an alkylamine oxide group,an alkylcarboxylate group or aminoalkyl group; and M⁺ is a cation, a H⁺atom or an ammonia group.
 17. An electrochromic device prepared by aprocess comprising the steps of: depositing a first conductive layerover a substrate; depositing a first electrode layer over the firstconductive layer, wherein the first electrode layer is one of anelectrochromic layer or a counter electrode layer; depositing an ionconductor layer over the first electrode layer, wherein a film stackincludes the first conductive layer, the first electrode layer, and theion conductor layer; exposing the ion conductor layer to a non-aqueousliquid to remove particulate material having a size between about 0.1 μmand about 1000 μm, wherein the non-aqueous liquid is selected from thegroup consisting of a hydrofluorocarbon, a fluorocarbon, a polymericfluorinated solvent, and a fluoride surfactant; depositing a secondelectrode layer over the film stack after exposing the ion conductorlayer to the non-aqueous liquid, wherein the second electrode layer isthe other of the electrochromic layer or the counter electrode layer;and depositing a second conductive layer on the second electrode layer,wherein the electrochromic device has a defect density of less than 1defect/m2, and wherein the electrochromic device is configured for usein a window.
 18. The electrochromic device of claim 17, wherein theelectrochromic device is configured to be part of an insulated glassunit.
 19. An electrochromic device prepared by a process comprising thesteps of: depositing a first conductive layer over a substrate;depositing a first electrode layer over the first conductive layer,wherein the first electrode layer is one of an electrochromic layer or acounter electrode layer; depositing an ion conductor layer over thefirst electrode layer, wherein a film stack includes the firstconductive layer, the first electrode layer, and the ion conductorlayer; exposing the ion conductor layer to a non-aqueous liquid toremove particulate material having a size between about 0.1 μm and about1000 μm, wherein the non-aqueous liquid is selected from the groupconsisting of a hydrofluorocarbon, a fluorocarbon, a polymericfluorinated solvent, and a fluoride surfactant, and wherein thenon-aqueous liquid comprises less than about 0.1% of water; depositing asecond electrode layer over the film stack after exposing the ionconductor layer to the non-aqueous liquid, wherein the second electrodelayer is the other of the electrochromic layer or the counter electrodelayer; and depositing a second conductive layer on the second electrodelayer, wherein the electrochromic device has a defect density of lessthan 1 defect/m2.
 20. The electrochromic device of claim 19, wherein theelectrochromic device is configured for use in a window.